Switch mount and protector



Dec. 13, 1966 LUlK 3,291,953

SWITCH MOUNT AND PROTECTOR Filed May 21, 1964 2 Sheets-Sheet l I 4: BY mM/ gi fl arr/vars:

Dec. 13, 1966 F. D. LUIK 3,291,953

SWITCH MOUNT AND PROTECTOR Filed May 21, 1964 2 Sheets-Sheet 2 INVENTQR.

United States Patent Ofitice 3,291,953 Patented Dec. 13, 1966 3,291,953SWITCH MOUNT AND PROTECTOR Frank D. Luik, Clawson, Mich., assignor toArtco Inc., Fraser, Mich., a corporation of Michigan Filed May 21, 1964,Ser. No. 369,270 8 Claims. (Cl. 200172) This invention relates todevices for actuating and protecting electrical switches.

Limit switches are used in industry in various applications and arefrequently used in situations requiring repetitive actuation as by aplurality of trip arms, etc., on a conveyor line. In such applicationsthe limit switch is continuously subject to shock, vibration, etc., and,being of a mechanical construction for essentially light duty operation,is susceptible to rapid wear, damage, loss of adjustment, etc. It is anobject of this invention to provide an actuating mechanism for use witha limit switch which isolates the limit switch from direct contact withthe trip arms, as on conveyor lines, and which mechanism is of a heavyduty, rugged construction to more readily withstand shock, vibration,etc., and which mechanism protects the limit switch from dam-age.

It is a general object of this invention to provide a device of a noveland improved construction for actuating and protecting limit switches.

Other objects, features, and advantages of the present invention willbecome apparent from the subsequent description and the appended claims,taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a pictorial view depicting a preferred form of the limitswitch protecting and actuating device in assembly relationship with aconveyor line;

FIGURE 2 is a pictorial view of a body member of the device of FIGURE 1;

FIGURE 3 is a front elevational view of the limit switch protecting andactuating device of FIGURE 1 with parts shown broken away and othersshown in section;

FIGURE 4 is a side elevational view of the assembly of FIGURE 3 takensubstantially along the line 44;

FIGURE 5 is a front elevational view of the limit switch protecting andactuating device of FIGURES 14 shown in assembly relationship with anadapter member permitting selectable adjustment of the location of theprotecting and actuating device;

FIGURE 6 is a top elevational view to reduced scale of the adaptermember of FIGURE 5 shown with portions of the protecting and actuatingdevice depicted in phantom; and

FIGURE 7 is a fragmentary front elevational view of a modified form ofthe limit switch protecting and actuating device of FIGURES 14 for usewith a pair of limit switches.

Looking now to FIGURES 1-4, a limit switch actuating and protectingdevice is generally indicated by the numeral 10 and is shown in assemblyrelationship with an assembly line (partially shown) which includes aframe member 12 and a convey-or line 14 which is movable relativelythereto in the direction of the arrow A. The device 10 in generalincludes a mounting plate 16, a body member 18 and a cam lever 20, allof which are of heavy cross-sections for rugged operation. The mountingplate 16 is elongated and generally rectangularly, uniformly shaped andcan be secured to the frame 12 by screws or welding and provides meansfor attaching the device 10 to the frame 12. The mounting plate 16 has apair of threaded bores 22 which are located substantially centrallylaterally and permit the body member 18 to be mounted to and selectivelypositioned on the mounting plate 16 in a manner to be presently seen.The body member 18 (FIGURE 2) has a back wall 23 with a longitudinallyextending slide groove 24 in its rear surface of a width substantiallyequal to the width of the mounting plate 16; the groove 24 receives thefront portion of the mounting plate 16 and acts as a guide inpositioning the body member 18 along one axis, up or down as shown inFIGURES l-4. The back wall 23 of the body member 18 has a longitudinallyextending through slot 26 which, with the body member 18 located on theplate 16, is in line with the threaded bores 22. A flat, elongatedretainer plate 28 is located on the forward surface of the back wall 23and has a pair of holes 30 spaced identically with threaded bores 22 inmounting plate 16 and is secured thereto by bolts 32 which extendthrough the holes 30 and through slot 26 thereby clamping the bodymember 18 to the mounting plate 16. It can be seen that while theretainer plate 28 is fixed to the mounting plate 16, the body member 18can be slidab'ly positioned along the mounting plate 16 simply byloosening the bolts 32. In this regard, the width of the slide groove 24is accurately formed relative to the width of the mounting plate 16 sothat precise up-and-down adjustments can be made.

The body member 18 is symmetrical about a longitudinal center line andhas a pair of longitudinally extending, downwardly tapering side ribs 34which extend transversely, outwardly from opposite sides of the backwall 23. The back wall 23 and side ribs 34 are connected at their upperends by a top portion 36 which includes a pair of upwardly extending,transversely spaced lugs 38, which have transversely extending, alignedbores 40. In between the lugs 38 are located laterally, outwardlyextending, downwardly inclined stop surfaces 42 which have downwardlyextending bores 44; a coil spring 46 and a removable plug 47 are locatedin different ones of the bores 46 and serve a purpose to be presentlydescribed.

The cam lever 20 is pivotally mounted between the lugs 36 by a pin 48which extends through the bores 44 in lugs 38 and through a bore 49(FIGURES 3 and 4) in the lever 20. The pin 48 is secured to lugs 38 atits opposite ends by cotter pins 50; a bearing of sintered metal orother suitable construction can be located between the pin 48 and thebore 49 in the lever 20.

The cam lever 20 has an arm portion 52 which extends to one side of bore49 and is mounted to body member 16 with the arm portion 52 extendingtoward the side with the spring 46; the arm portion 52 has upper andlower earn surfaces 54 and 56, respectively. A stop engaging surface 58(FIGURE 3) is located on the arm side of the bore 49 and is inconfrontation with the stop surface 42 on that side of body member 16. Aprojection 60 extends from the stop engaging surface 58 and extends pa;-tially within the coil spring 46 to prevent the spring 46 from sliding.The spring 46 is in precompression and normally urges the arm portion 52upwardly or in a counterclockwise direction, as viewed in FIGURES 1-4,to a posit-ion determined by the point of engagement of a projection 62on the cam lever 52 at the opposite side of the bore 49 with the plug47. The travel of the cam lever 20, and hence arm portion 52, in anopposite, clockwise, direction is limited to a position at which thestop engaging surface 58 on arm portion 52 engages the stop surface 42on that side of the body member 18.

A limit switch 64, which can be of a construction well known in the art,is mounted to an attachment plate 66 which in turn is mounted to one ofthe side ribs 34 via bolts 68. Each of the side ribs 34 is provided witha pair of similarly located laterally extending through bores 70 forbolts 68 whereby a switch, such as switch 64, and plate 66 can bemounted to either side. As shown in FIG- URES 1-4, the switch 64 ismounted on the right side of body member 18 and, of course, the camlever 20 is mounted with its arm portion 52 extending to the right. If aswitch, such as switch 64, and plate 66 were mounted on the left side ofbody member 16 then the cam lever 20 would be mounted with the armportion 52 extending to the left; at the same time, the spring 46 andplug 47 would be interchanged in their respective bores 44.

A switch arm 72 is pivotally mounted on the switch 64 and is movablebetween extreme positions tor actuating or deactuating the circuit ofswitch 634. The switch arm 72 has a cam roller 7-4 at its outer endwhich is continuously, resiliently urged (by conventional means notshown) into engagement with the lower cam surface 46 on arm portion 52.Thus as the cam lever 20 is moved between the positions fixed by itsstops the switch arm 72 is moved between its extreme positions.

In operation a plurality of trip arms, such as arm 76, can be fixed tothe conveyor line 14 and positioned so as to engage the upper camsurface 54 as the conveyor 14 moves in the direction of the arrow A topivot the cam lever 20 clockwise, and hence to move the switch arm 72 toone extreme position (as shown in phantom in FIGURE 3). As the trip arm76 moves out of engagement with the arm portion 52, the spring 46 movesthe cam lever 20 to its opposite extreme position, with the switch arm72 following to its other extreme position.

Note that, with the device 10, the delicate limit switch 64 is notsubjected to the shock loads as by direct engagement with the trip arms76 and the initial impact loads, etc., are taken by the rugged cam lever20. In addition, the clockwise movement of the cam lever 20 is limitedby the positive stop provided by surfaces 42 and 58 on the body member18 and cam lever 20, respectively; hence the switch arm 72 cannot beoverdriven thus protecting the limit switch 64. As previously noted, thedevice 10 can be readily converted !for use with a limit switch on theopposite side while still utilizing the same basic elements.

With the apparatus of FIGURES 1-4 the position of the body member '18,and hence the switch 64, can be adjusted along one axis, i.e.,vertically up or down. In FIGURES and 6 the use of an adapter 78 permitsad justment along a second axis to permit both vertical and horizontalpositioning. In the combination shown in FIGURES 5 and 6, the mountingplate 16 is mounted with its longitudinal axis extending horizontally.The adapter 78 is generally rectangularly shaped and is elongated and issecured to the mounting plate 16 with its longitudinal axis extendinghorizontally. The adapter 78 has a longitudinally extending slide groove80 in its rear surface of a width substantially equal to the width ofthe mounting plate 16; the groove 80 receives the front portion of themounting plate 16 and acts as a guide in horizontally positioning theadapter 78. A longitudinally extending through slot 82 extends throughthe adapter 78 whereby the adapter 78 can be adjustably clamped to themounting plate '16 via a hat retaining plate 84 (similar to retainingplate 23) and a pair of bolts 86. The adapter 78 has a pair oflongitudinally extending ribs 88 on opposite sides which are connectedat one extremity to a transversely, outwardly extending guide blockportion 90. The guide block portion 90 is of a width to matably fitwithin the slide groove 24 in the body member 1 8 and has apair ofthreaded bores 92 which are spaced to receive the bolts 32 whereby thebody member 18 can be adjustably clamped thereto via the retaining plate23 and the vertical position of the body member can be adjusted. Asubstantial range of horizontal adjustments can be obtained with thecombination of FIGURES 5 and 6 since the adapter 78 can be assembled toextend to the left or to the right. In the combination of FIGURES 5 and6 the attachment plate 66 and limit switch 64 have been omitted for thesake of clairty, it being understood that these elements can beconnected to the body member 18 in the manner shown in FIG- URES 1-4 andas previously described.

A further variation of the apparatus of FIGURES 1-4 is shown in FIGURE7. In FIGURE 7 a second limit switch 64a and mounting plate 66a aresecured to the left sideof the body member 18. A second spring 46a issubstituted for the plug 47 in the associated bore 44 and a cam lever20a is substituted :for the cam lever (20. The cam lever 20a issubstantially symmetrically constructed about a vertical axis and has apair of arm portions 52a extending in opposite directions from a centeractuation lever portion 94. The arm portions 5 2a are engaged by the camrollers on the switch arms of the limit switches 64, 64a whereby pivotalmovement of the cam lever 20a in one direction or the other as appliedto the lever portion 94 causes actuation or tie-actuation of the limitswitches 64, 64a. The cam lever 20a is provided with a pair of stopengaging surfaces 58a for engaging the stop surfaces 42 on the bodymember -18 to provide a positive stop in either direction whereby bothswitches 64, 64a are protected. The springs 46 and 46a are seated inbores in the associated stop engaging surfaces 58a and are under aprecompression to maintain .the cam lever 20a centered; however, thesprings 46, 46a can be selected such as to normally place the cam lever20a in one of the other extreme positions, i.e., right or left.Substantial variations in circuit arrangement of switches 64, 64a canalso be obtained.

While it will be apparent that the preferred embodiments of theinvention disclosed are well calculated to fulfill the objects abovestated, it will be appreciated that the invention is susceptible tomodification, variation and change without departing [from the properscope or fair meaning of the subjoined claims.

What is claimed is:

1. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a heavy sectioned body member,means on said body member {or supporting a limit switch to said bodymember, a heavy sectioned lever member adapted to be enagageable withthe switch arm and pivotally secured to said body member for pivotalmovement about a selected axis towards and away from the limit switch,first stop means comprising a pair of engageable surfaces on said levermember and said body member for limiting the movement of said levermember in a direction away from the limit switch, and second stop meanson said lever member and said body member for limiting the movement ofsaid lever member in a direction towards the limit switch whereby damageto the limit switch is prevented from overtravel of said lever membersaid first and second stop means substantially symmetrically lo cated onopposite sides of said axis whereby said lever member can be utilized toactuate a limit switch located 1 on either side of said selected axis.

2. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a heavy sectioned body member,means on said body member for supporting a limit switch .to said bodymember, a heavy sectioned lever member adapted to be engageable with theswitch arm and pivotally secured to said body member for pivotalmovement about a selected axis towards and away from the limit switch,first stop means comprising a pair of engageable surfaces on said levermember and said body member for limiting the movement of said levermember in a direction away from the limit switch, second stop means onsaid lever member and said body member for limiting the movement of saidlever member in a direction towards the limit switch whereby damage tothe limit switch is prevented from overtravel of said lever member, andspring means for resiliently unging said lever member to the limitposition established by said first stop means said first and second stopmeans substantially sy-mmetrically located on opposite sides of saidaxis whereby said lever member can be utilized to actuate a limit switchlocated on either side of said selected axis.

3. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a heavy sectioned body member,means on said body member for supporting a pair of limit switches onopposite sides of said body member, a heavy sectioned lever memberadapted to be engageable with the switch arms of both limit switches andpivotally secured to said body member for pivotal movement in onedirection toward one and away from the other of the limit switches andin an opposite direction away from the one and toward the other of thelimit switches, stop means on said lever member and said body member forlimiting the movement of said lever member in said one and said oppositedirections whereby damage to the limit switch is prevented, and springmeans simultaneously urging said lever member in said one and saidopposite direction.

4. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a heavy sectioned body memberhaving a substantially symmetrical construction relative to one axis,means on said body member for supporting a limit switch to either of twosides of said body member on opposite sides of said one axis, a heavysectioned lever member having a pivot support and having an arm portionextending away from said pivot support, and means for pivotally securingsaid lever member to said body member at said pivot support with saidarm portion extending in a direction towards either of said two sides ofsaid body member and with said arm portion adapted to be in closeproximity with the switch arm of the limit switch and for pivotalmovement towards and away from the limit switch.

5. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a heavy sectioned body memberhaving a substantially symmetrical construction relative to one axis,means on said body member for supporting a limit switch to either of twosides of said body member on opposite sides of said one axis, a heavysectioned lever member having a pivot support and having an arm portionextending away from said pivot support, means for pivotally securingsaid lever member to said body member at said pivot support with saidarm portion extending in a direction towards either of said two sides ofsaid body member and with said arm portion adapted to be in closeproximity with the switch arm of the limit switch and for pivotalmovement towards and away from the limit switch, first stop means onsaid lever member and said body member for limiting the movement of saidlever member in a direction away from the limit switch, second stopmeans on said lever member and said body member for limiting themovement of said lever member in a direction towards the limit switchwhereby damage to the limit switch is prevented from overtravel of saidlever member, and spring means for resiliently urging said lever memberto the limit position established by said first stop means.

6. An actuating and rotecting device adapted to be mounted to a supportmember for protecting and actuating a limit switch having a switch armmovable for actuating and deactuating the limit switch, said devicecomprising: a heavy sectioned body member having a substantiallysymmetrical construction relative to one axis, means on said body memberfor supporting a limit switch to either of two sides of said body memberon opposite sides of said one axis, a heavy sectioned lever memberhaving a pivot support, means for pivotal-1y securing said lever memberto said body member at said pivot support with said arm portionextending in a direction towards either of said two sides of said bodymember and with said arm portion adapted to be in close proximity withthe switch arm of the limit switch and for pivotal movement towards andaway from the'limit switch, first stop means on said lever member andsaid body member for limiting the movement of said lever member in adirection away from the limit switch, second stop means on said levermember and said body member for limiting the movement of said levermember in a direction towards the limit switch whereby damage to thelimit switch is prevented from overtravel of said lever member, springmeans for resiliently urging said lever member to the limit positionestablished by said first stop means, and means for supporting said bodymember on the support member and permitting selective adjustment of saidbody member relative to the support member along two mutuallyperpendicular axes.

7. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a longitudinally extending,generally rectangularly shaped support plate, a longitudinally extendingbody member having a longitudinally extending slide groove of a contourfor matably receiving the forward surface of said support plate, saidbody member having a longitudinally extending through slot incommunication with said slide groove, means operatively connected withsaid slot for clamping said body member to said support plate and forpermitting selective relative movement of said body member with saidsupport plate along said slot, a lever member adapted to be engageablewith the switch arm and pivotally secured to said body member forpivotal movement about a selected axis towards and away from the limitswitch, a first stop surface on said body member, a first stop engagingsurface on said lever member in confrontation with said first stopsurface and adapted to be engageable with said first stop surface forlimiting the movement of said lever member in a direction towards thelimit switch whereby damage to the limit switch is prevented fromovertravel of said lever member, a second stop surface on said bodymember, a second stop engaging surface on said lever member in aconfrontation with said stop surface and adapted to be engageable withsaid stop surface for limiting the movement of said lever member in adirection away from the limit switch, and spring means located betweensaid first stop surface and said first stop engaging surface for urgingsaid second stop engaging surface into engagement with said second stopsurface said first and second stop means substantially symmetricallylocated on opposite sides of said axis whereby said lever member can beutilized to actuate a limit switch located on either side of saidselected axis.

8. An actuating and protecting device for protecting and actuating alimit switch having a switch arm movable for actuating and deactuatingthe limit switch, said device comprising: a heavy sectioned body member,means for attaching a pair of limit switches to opposite sides of saidbody member, a heavy sectioned lever member having a pair of oppositelyextending arm portions each adapted to be engageable with one of thelimit switches and being pivotally secured to said body member forpivotal movement alternatively towards one or the other limit switch, afirst stop surface on said body member, a first stop engaging surface onone of said arm portions in confrontation with said first stop surfaceand engageable with said first stop surface for limiting the movement ofsaid one of said arm portions towards its associated limit switch, asecond stop surface on said body member, a second stop engaging surfaceon the other of said arm portions in confrontation with said second stopsurface and engageable with said second stop surface for limiting themovement of said other of said arm portions towards its associated limitswitch, first spring means located between said first stop surface andsaid first stop engaging surface for urging said other of said armportions towards its associated limit switch, and second spring meanslocated between said second 7 8 stop surface and said second stopengaging surface for 3,156,805 11/1964 Baker et a1. 200--168 X urgingsaid one of said arm portions towards its as- 3,198,925 8/1965Starrantino 200172 sociated limit switch.

ROBERT K. SCHAEFER, Primary Examiner. References Cited by the Examiner 5KATHLEEN H CLAFFY, Examiner.

UNITED STATES PATENTS H. 0. JONES, Assistant Examiner.

2,338,365 1/1944 Thorp et a1. 200-172

1. AN ACTUATING AND PROTECTING DEVICE FOR PROTECTING AND ACTUATING ALIMIT SWITCH HAVING A SWITCH ARM MOVABLE FOR ACTUATING AND DEACTUATINGTHE LIMIT SWITCH, SAID DEVICE COMPRISING: A HEAVY SECTIONED BODY MEMBER,MEANS ON SAID BODY MEMBER FOR SUPPORTING A LIMIT SWITCH TO SAID BODYMEMBER, A HEAVY SECTIONED LEVER MEMBER ADAPTED TO BE ENGAGEABLE WITH THESWITCH ARM AND PIVOTALLY SECURED TO SAID BODY MEMBER FOR PIVOTALMOVEMENT ABOUT A SELECTED AXIS TOWARDS AND AWAY FROM THE LIMIT SWITCH,FIRST STOP MEANS COMPRISING A PAIR OF ENGAGEABLE SURFACES ON SAID LEVERMEMBER AND SAID BODY MEMBER FOR LIMITING THE MOVEMENT OF SAID LEVERMEMBER IN A DIRECTION AWAY FROM THE LIMIT SWITCH, AND SECOND STOP MEANSON SAID LEVER MEMBER AND SAID BODY MEMBER FOR LIMITING THE MOVEMENT OFSAID LEVER MEMBER IN A DIRECTION TOWARDS THE LIMIT SWITCH WHEREBY DAMAGETO THE LIMIT SWITCH IS PREVENTED FROM OVERTRAVEL OF SAID LEVER MEMBERSAID FIRST AND SECOND STOP MEANS SUBSTANTIALLY SYMMETRICALLY LOCATED ONOPPOSITE SIDES OF SAID AXIS WHEREBY SAID LEVER MEMBER CAN BE UTILIZED TOACTUATE A LIMIT SWITCH LOCATED ON EITHER SIDE OF SAID SELECTED AXIS.